Merge abarkov@build.mysql.com:/home/bk/mysql-4.1

into bar.mysql.r18.ru:/usr/home/bar/mysql-4.1

sql/item.cc

@@ -39,8 +39,7 @@ Item::Item():
 {
   marker= 0;
   maybe_null=null_value=with_sum_func=unsigned_flag=0;
-  collation= &my_charset_bin;
-  coercibility= COER_COERCIBLE;
+  set_charset(&my_charset_bin, DERIVATION_COERCIBLE);
   name= 0;
   decimals= 0; max_length= 0;
   THD *thd= current_thd;
@@ -68,8 +67,7 @@ Item::Item(THD *thd, Item &item):
   unsigned_flag(item.unsigned_flag),
   with_sum_func(item.with_sum_func),
   fixed(item.fixed),
-  collation(item.collation),
-  coercibility(item.coercibility)
+  collation(item.collation)
 {
   next=thd->free_list;			// Put in free list
   thd->free_list= this;
@@ -185,12 +183,12 @@ CHARSET_INFO * Item::default_charset() const
   return current_thd->variables.collation_connection;
 }
 
-bool Item::set_charset(CHARSET_INFO *cs1, enum coercion co1,
-		       CHARSET_INFO *cs2, enum coercion co2)
+bool Item::set_charset(CHARSET_INFO *cs1, Derivation co1,
+		       CHARSET_INFO *cs2, Derivation co2)
 {
   if (cs1 == &my_charset_bin || cs2 == &my_charset_bin)
   {
-    set_charset(&my_charset_bin, COER_NOCOLL);
+    set_charset(&my_charset_bin, DERIVATION_NONE);
     return 0;
   }
 
@@ -209,7 +207,7 @@ bool Item::set_charset(CHARSET_INFO *cs1, enum coercion co1,
   {
     if (cs1 != cs2)
     {
-      if (co1 == COER_EXPLICIT)
+      if (co1 == DERIVATION_EXPLICIT)
       {
         return 1;
       }
@@ -218,7 +216,7 @@ bool Item::set_charset(CHARSET_INFO *cs1, enum coercion co1,
         CHARSET_INFO *bin= get_charset_by_csname(cs1->csname, MY_CS_BINSORT,MYF(0));
         if (!bin)
 	  return 1;
-        set_charset(bin, COER_NOCOLL);
+        set_charset(bin, DERIVATION_NONE);
       }
     }
     else
@@ -230,7 +228,7 @@ bool Item::set_charset(CHARSET_INFO *cs1, enum coercion co1,
 Item_field::Item_field(Field *f) :Item_ident(NullS,f->table_name,f->field_name)
 {
   set_field(f);
-  coercibility= COER_IMPLICIT;
+  set_charset(DERIVATION_IMPLICIT);
   fixed= 1; // This item is not needed in fix_fields
 }
 
@@ -239,7 +237,7 @@ Item_field::Item_field(THD *thd, Item_field &item):
   Item_ident(thd, item),
   field(item.field),
   result_field(item.result_field)
-{ coercibility= COER_IMPLICIT; }
+{ set_charset(DERIVATION_IMPLICIT); }
 
 void Item_field::set_field(Field *field_par)
 {
@@ -251,7 +249,7 @@ void Item_field::set_field(Field *field_par)
   field_name=field_par->field_name;
   db_name=field_par->table->table_cache_key;
   unsigned_flag=test(field_par->flags & UNSIGNED_FLAG);
-  set_charset(field_par->charset(), COER_IMPLICIT);
+  set_charset(field_par->charset(), DERIVATION_IMPLICIT);
 }
 
 const char *Item_ident::full_name() const
@@ -1102,7 +1100,7 @@ Item_varbinary::Item_varbinary(const char *str, uint str_length)
     str+=2;
   }
   *ptr=0;					// Keep purify happy
-  coercibility= COER_COERCIBLE;
+  set_charset(&my_charset_bin, DERIVATION_COERCIBLE);
 }
 
 longlong Item_varbinary::val_int()

sql/item.h

@@ -23,6 +23,63 @@ class Protocol;
 struct st_table_list;
 void item_init(void);			/* Init item functions */
 
+
+/*
+   "Declared Type Collation"
+   A combination of collation and its deriviation.
+*/
+
+enum Derivation
+{
+  DERIVATION_COERCIBLE= 3,
+  DERIVATION_IMPLICIT= 2,
+  DERIVATION_NONE= 1,
+  DERIVATION_EXPLICIT= 0
+};
+
+class DTCollation {
+public:
+  CHARSET_INFO     *collation;
+  enum Derivation derivation;
+  
+  DTCollation()
+  {
+    collation= &my_charset_bin;
+    derivation= DERIVATION_NONE;
+  }
+  DTCollation(CHARSET_INFO *collation_arg, Derivation derivation_arg)
+  {
+    collation= collation_arg;
+    derivation= derivation_arg;
+  }
+  void set(DTCollation *dt)
+  { 
+    collation= dt->collation;
+    derivation= dt->derivation;
+  }
+  void set(CHARSET_INFO *collation_arg, Derivation derivation_arg)
+  {
+    collation= collation_arg;
+    derivation= derivation_arg;
+  }
+  void set(CHARSET_INFO *collation_arg)
+  { collation= collation_arg; }
+  void set(Derivation derivation_arg)
+  { derivation= derivation_arg; }
+  bool aggregate(DTCollation *dt);
+  const char *derivation_name() const
+  {
+    switch(derivation)
+    {
+      case DERIVATION_COERCIBLE: return "COERCIBLE";
+      case DERIVATION_IMPLICIT:  return "IMPLICIT";
+      case DERIVATION_EXPLICIT:  return "EXPLICIT";
+      case DERIVATION_NONE:      return "NONE";
+      default: return "UNKNOWN";
+    }
+  }
+};
+
 class Item {
   uint loop_id;                         /* Used to find selfrefering loops */
   Item(const Item &);			/* Prevent use of these */
@@ -41,19 +98,6 @@ class Item {
              SUBSELECT_ITEM, ROW_ITEM, CACHE_ITEM};
 
   enum cond_result { COND_UNDEF,COND_OK,COND_TRUE,COND_FALSE };
-  enum coercion    { COER_COERCIBLE=3, COER_IMPLICIT=2,
-		     COER_NOCOLL=1,    COER_EXPLICIT=0  };
-  const char *coercion_name(enum coercion coer) const
-  {
-    switch(coer)
-    {
-      case COER_COERCIBLE: return "COERCIBLE";
-      case COER_IMPLICIT:  return "IMPLICIT";
-      case COER_EXPLICIT:  return "EXPLICIT";
-      case COER_NOCOLL:    return "NO COLLATION";
-      default: return "UNKNOWN";
-    }
-  }
   
   String str_value;			/* used to store value */
   my_string name;			/* Name from select */
@@ -65,9 +109,8 @@ class Item {
   my_bool unsigned_flag;
   my_bool with_sum_func;
   my_bool fixed;                        /* If item fixed with fix_fields */
-  CHARSET_INFO  *collation;		/* character set && collation    */
-  enum coercion coercibility;		/* Precedence order of collation */
-
+  DTCollation collation;
+  
   // alloc & destruct is done as start of select using sql_alloc
   Item();
   /*
@@ -125,13 +168,23 @@ class Item {
   virtual Item *get_tmp_table_item(THD *thd) { return copy_or_same(thd); }
 
   CHARSET_INFO *default_charset() const;
-  CHARSET_INFO *charset() const { return collation; };
+  Derivation derivation() const { return collation.derivation; }
+  CHARSET_INFO *charset() const { return collation.collation; }
   void set_charset(CHARSET_INFO *cs) 
-  { collation= cs; }
-  void set_charset(CHARSET_INFO *cs, enum coercion coer)
-  { collation= cs; coercibility= coer; }
-  bool set_charset(CHARSET_INFO *cs1, enum coercion co1, 
-  		   CHARSET_INFO *cs2, enum coercion co2);
+  { collation.collation= cs; }
+  void set_charset(Derivation dv) 
+  { collation.derivation= dv; }
+  void set_charset(CHARSET_INFO *cs, Derivation dv)
+  { collation.collation= cs; collation.derivation= dv; }
+  void set_charset(Item &item)
+  { collation= item.collation; }
+  void set_charset(DTCollation *collation_arg)
+  { 
+    collation.collation= collation_arg->collation; 
+    collation.derivation= collation_arg->derivation;
+  }
+  bool set_charset(CHARSET_INFO *cs1, Derivation dv1, 
+  		   CHARSET_INFO *cs2, Derivation dv2);
   bool binary() const
   { return charset()->state & MY_CS_BINSORT ? 1 : 0 ; }
   
@@ -180,7 +233,7 @@ class Item_field :public Item_ident
   Item_field(const char *db_par,const char *table_name_par,
 	     const char *field_name_par)
     :Item_ident(db_par,table_name_par,field_name_par),field(0),result_field(0)
-  { coercibility= COER_IMPLICIT; }
+  { set_charset(DERIVATION_IMPLICIT); }
   // Constructor need to process subselect with temporary tables (see Item)
   Item_field(THD *thd, Item_field &item);
   Item_field(Field *field);
@@ -381,21 +434,19 @@ class Item_string :public Item
 {
 public:
   Item_string(const char *str,uint length,
-  	      CHARSET_INFO *cs, enum coercion coer= COER_COERCIBLE)
+  	      CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE)
   {
-    set_charset(cs);
+    set_charset(cs, dv);
     str_value.set(str,length,cs);
-    coercibility= coer;
     max_length=length;
     set_name(str, length, cs);
     decimals=NOT_FIXED_DEC;
   }
   Item_string(const char *name_par, const char *str, uint length,
-	      CHARSET_INFO *cs, enum coercion coer= COER_COERCIBLE)
+	      CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE)
   {
-    set_charset(cs);
+    set_charset(cs, dv);
     str_value.set(str,length,cs);
-    coercibility= coer;
     max_length=length;
     set_name(name_par,0,cs);
     decimals=NOT_FIXED_DEC;

sql/item_cmpfunc.cc

@@ -23,6 +23,15 @@
 
 #include "mysql_priv.h"
 #include <m_ctype.h>
+
+static void my_coll_agg_error(DTCollation &c1, DTCollation &c2, const char *fname)
+{
+  my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
+  	   c1.collation->name,c1.derivation_name(),
+	   c2.collation->name,c2.derivation_name(),
+	   fname);
+}
+
 Item_bool_func2* Item_bool_func2::eq_creator(Item *a, Item *b)
 {
   return new Item_func_eq(a, b);
@@ -87,13 +96,13 @@ static bool convert_constant_item(Field *field, Item **item)
   return 0;
 }
 
-bool Item_bool_func2::set_cmp_charset(CHARSET_INFO *cs1, enum coercion co1,
-				      CHARSET_INFO *cs2, enum coercion co2)
+bool Item_bool_func2::set_cmp_charset(CHARSET_INFO *cs1, Derivation co1,
+				      CHARSET_INFO *cs2, Derivation co2)
 {
   if (cs1 == &my_charset_bin || cs2 == &my_charset_bin)
   {
     cmp_charset= &my_charset_bin;
-    coercibility= co1 > co2 ? co1 : co2;
+    //coercibility= co1 > co2 ? co1 : co2;
     return 0;
   }
 
@@ -106,42 +115,42 @@ bool Item_bool_func2::set_cmp_charset(CHARSET_INFO *cs1, enum coercion co1,
     if ((co1 <= co2) && (cs1==&my_charset_bin))
     {
       cmp_charset= cs1;
-      coercibility= co1;
+      //coercibility= co1;
     }
     else if ((co2 <= co1) && (cs2==&my_charset_bin))
     {
       cmp_charset= cs2;
-      coercibility= co2;
+      //coercibility= co2;
     }
     else
     {
       cmp_charset= 0;
-      coercibility= COER_NOCOLL;
+      //coercibility= DERIVATION_NOCOLL;
       return 1; 
     }
   }
   else if (co1 < co2)
   {
     cmp_charset= cs1;
-    coercibility= co1;
+    //coercibility= co1;
   }
   else if (co2 < co1)
   {
     cmp_charset= cs2;
-    coercibility= co1;
+    //coercibility= co1;
   }
   else
   { 
     if (cs1 == cs2)
     {
       cmp_charset= cs1;
-      coercibility= co1;
+      //coercibility= co1;
     }
     else 
     {
-      coercibility= COER_NOCOLL;
+      //coercibility= DERIVATION_NOCOLL;
       cmp_charset= 0;
-      return  (co1 == COER_EXPLICIT) ? 1 : 0;
+      return  (co1 == DERIVATION_EXPLICIT) ? 1 : 0;
     }
   }
   return 0;
@@ -171,13 +180,13 @@ bool Item_bool_func2::fix_fields(THD *thd, struct st_table_list *tables,
     uint strong= 0;
     uint weak= 0;
 
-    if ((args[0]->coercibility < args[1]->coercibility) && 
+    if ((args[0]->derivation() < args[1]->derivation()) && 
 	!my_charset_same(args[0]->charset(), args[1]->charset()) &&
         (args[0]->charset()->state & MY_CS_UNICODE))
     {
       weak= 1;
     }
-    else if ((args[1]->coercibility < args[0]->coercibility) && 
+    else if ((args[1]->derivation() < args[0]->derivation()) && 
 	     !my_charset_same(args[0]->charset(), args[1]->charset()) &&
              (args[1]->charset()->state & MY_CS_UNICODE))
     {
@@ -194,26 +203,23 @@ bool Item_bool_func2::fix_fields(THD *thd, struct st_table_list *tables,
         cstr.copy(ostr->ptr(), ostr->length(), ostr->charset(), 
 		  args[strong]->charset());
         conv= new Item_string(cstr.ptr(),cstr.length(),cstr.charset(),
-			      args[weak]->coercibility);
+			      args[weak]->derivation());
 	((Item_string*)conv)->str_value.copy();
       }
       else
       {
 	conv= new Item_func_conv_charset(args[weak],args[strong]->charset());
-        conv->coercibility= args[weak]->coercibility;
+        //conv->coercibility= args[weak]->derivation();
       }
       args[weak]= conv ? conv : args[weak];
-      set_cmp_charset(args[0]->charset(), args[0]->coercibility,
-		      args[1]->charset(), args[1]->coercibility);
+      set_cmp_charset(args[0]->charset(), args[0]->derivation(),
+		      args[1]->charset(), args[1]->derivation());
     }
   }
   if (!cmp_charset)
   {
     /* set_cmp_charset() failed */
-    my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     args[0]->charset()->name,coercion_name(args[0]->coercibility),
-	     args[1]->charset()->name,coercion_name(args[1]->coercibility),
-	     func_name());
+    my_coll_agg_error(args[0]->collation, args[1]->collation, func_name());
     return 1;
   }
   return 0;
@@ -266,8 +272,8 @@ void Item_bool_func2::fix_length_and_dec()
     We must set cmp_charset here as we may be called from for an automatic
     generated item, like in natural join
   */
-  set_cmp_charset(args[0]->charset(), args[0]->coercibility,
-		  args[1]->charset(), args[1]->coercibility);
+  set_cmp_charset(args[0]->charset(), args[0]->derivation(),
+		  args[1]->charset(), args[1]->derivation());
 }
 
 
@@ -744,12 +750,9 @@ Item_func_ifnull::fix_length_and_dec()
 					  args[1]->result_type())) !=
       REAL_RESULT)
     decimals= 0;
-  if (set_charset(args[0]->charset(),args[0]->coercibility,
-		  args[1]->charset(),args[1]->coercibility))
-    my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     args[0]->charset()->name,coercion_name(args[0]->coercibility),
-	     args[1]->charset()->name,coercion_name(args[1]->coercibility),
-	     func_name());
+  if (set_charset(args[0]->charset(),args[0]->derivation(),
+		  args[1]->charset(),args[1]->derivation()))
+    my_coll_agg_error(args[0]->collation, args[1]->collation, func_name());
 }
 
 
@@ -825,13 +828,10 @@ Item_func_if::fix_length_and_dec()
   else if (arg1_type == STRING_RESULT || arg2_type == STRING_RESULT)
   {
     cached_result_type = STRING_RESULT;
-    if (set_charset(args[1]->charset(), args[1]->coercibility,
-		args[2]->charset(), args[2]->coercibility))
+    if (set_charset(args[1]->charset(), args[1]->derivation(),
+		args[2]->charset(), args[2]->derivation()))
     {
-      my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     args[0]->charset()->name,coercion_name(args[0]->coercibility),
-	     args[1]->charset()->name,coercion_name(args[1]->coercibility),
-	     func_name());
+      my_coll_agg_error(args[0]->collation, args[1]->collation, func_name());
       return;
     }
   }

sql/item_cmpfunc.h

@@ -123,8 +123,8 @@ class Item_bool_func2 :public Item_int_func
   {
     cmp.set_cmp_func(this, tmp_arg, tmp_arg+1);
   }
-  bool set_cmp_charset(CHARSET_INFO *cs1, enum coercion co1, 
-  		       CHARSET_INFO *cs2, enum coercion co2);
+  bool set_cmp_charset(CHARSET_INFO *cs1, Derivation co1, 
+  		       CHARSET_INFO *cs2, Derivation co2);
   optimize_type select_optimize() const { return OPTIMIZE_OP; }
   virtual enum Functype rev_functype() const { return UNKNOWN_FUNC; }
   bool have_rev_func() const { return rev_functype() != UNKNOWN_FUNC; }

sql/item_create.cc

@@ -450,7 +450,7 @@ Item *create_func_version(void)
 {
   return new Item_string(NullS,server_version, 
 			 (uint) strlen(server_version),
-			 system_charset_info, Item::COER_IMPLICIT);
+			 system_charset_info, DERIVATION_IMPLICIT);
 }
 
 Item *create_func_weekday(Item* a)

sql/item_func.cc

@@ -31,6 +31,14 @@
 #include <zlib.h>
 #endif
 
+static void my_coll_agg_error(DTCollation &c1, DTCollation &c2, const char *fname)
+{
+  my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
+  	   c1.collation->name,c1.derivation_name(),
+	   c2.collation->name,c2.derivation_name(),
+	   fname);
+}
+
 /* return TRUE if item is a constant */
 
 bool
@@ -859,14 +867,11 @@ void Item_func_min_max::fix_length_and_dec()
       maybe_null=0;
     cmp_type=item_cmp_type(cmp_type,args[i]->result_type());
     if (i==0)
-      set_charset(args[i]->charset(), args[i]->coercibility);
-    else if (set_charset(charset(), coercibility, 
-			args[i]->charset(), args[i]->coercibility))
+      set_charset(*args[i]);
+    else if (set_charset(charset(), derivation(), 
+			args[i]->charset(), args[i]->derivation()))
     {
-      my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     charset()->name,coercion_name(coercibility),
-	     args[i]->charset()->name,coercion_name(args[i]->coercibility),
-	     func_name());
+      my_coll_agg_error(collation, args[i]->collation, func_name());
       break;
     }
   }
@@ -1038,7 +1043,7 @@ longlong Item_func_coercibility::val_int()
     return 0;
   }
   null_value= 0;
-  return (longlong) args[0]->coercibility;
+  return (longlong) args[0]->derivation();
 }
 
 longlong Item_func_locate::val_int()
@@ -2000,7 +2005,7 @@ Item_func_set_user_var::fix_length_and_dec()
 void Item_func_set_user_var::update_hash(void *ptr, uint length,
 					 Item_result type,
 					 CHARSET_INFO *cs,
-					 enum coercion coercibility)
+					 Derivation dv)
 {
   if ((null_value=args[0]->null_value))
   {
@@ -2009,8 +2014,7 @@ void Item_func_set_user_var::update_hash(void *ptr, uint length,
       my_free(entry->value,MYF(0));
     entry->value=0;
     entry->length=0;
-    entry->var_charset=cs;
-    entry->var_coercibility= coercibility;
+    collation.set(cs, dv);
   }
   else
   {
@@ -2041,8 +2045,7 @@ void Item_func_set_user_var::update_hash(void *ptr, uint length,
     memcpy(entry->value,ptr,length);
     entry->length= length;
     entry->type=type;
-    entry->var_charset=cs;
-    entry->var_coercibility= coercibility;
+    entry->collation.set(cs, dv);
   }
   return;
 
@@ -2085,7 +2088,7 @@ Item_func_set_user_var::val()
 {
   double value=args[0]->val();
   update_hash((void*) &value,sizeof(value), REAL_RESULT, 
-    &my_charset_bin, COER_NOCOLL);
+    &my_charset_bin, DERIVATION_NONE);
   return value;
 }
 
@@ -2094,7 +2097,7 @@ Item_func_set_user_var::val_int()
 {
   longlong value=args[0]->val_int();
   update_hash((void*) &value, sizeof(longlong), INT_RESULT,
-	      &my_charset_bin, COER_NOCOLL);
+	      &my_charset_bin, DERIVATION_NONE);
   return value;
 }
 
@@ -2103,10 +2106,10 @@ Item_func_set_user_var::val_str(String *str)
 {
   String *res=args[0]->val_str(str);
   if (!res)					// Null value
-    update_hash((void*) 0, 0, STRING_RESULT, &my_charset_bin, COER_NOCOLL);
+    update_hash((void*) 0, 0, STRING_RESULT, &my_charset_bin, DERIVATION_NONE);
   else
     update_hash((void*) res->ptr(), res->length(), STRING_RESULT,
-		res->charset(), args[0]->coercibility);
+		res->charset(), args[0]->derivation());
   return res;
 }
 
@@ -2147,7 +2150,7 @@ Item_func_get_user_var::val_str(String *str)
     str->set(*(longlong*) entry->value, &my_charset_bin);
     break;
   case STRING_RESULT:
-    if (str->copy(entry->value, entry->length, entry->var_charset))
+    if (str->copy(entry->value, entry->length, entry->collation.collation))
     {
       null_value=1;
       return NULL;
@@ -2236,7 +2239,7 @@ void Item_func_get_user_var::fix_length_and_dec()
 	                     ALIGN_SIZE(sizeof(BINLOG_USER_VAR_EVENT));
       user_var_event->user_var_event= var_entry;
       user_var_event->type= var_entry->type;
-      user_var_event->charset_number= var_entry->var_charset->number;
+      user_var_event->charset_number= var_entry->collation.collation->number;
       if (!var_entry->value)
       {
 	/* NULL value*/

sql/item_func.h

@@ -943,7 +943,7 @@ class Item_func_set_user_var :public Item_func
   longlong val_int();
   String *val_str(String *str);
   void update_hash(void *ptr, uint length, enum Item_result type, 
-  		   CHARSET_INFO *cs, enum coercion coercibility);
+  		   CHARSET_INFO *cs, Derivation dv);
   bool update();
   enum Item_result result_type () const { return cached_result_type; }
   bool fix_fields(THD *thd, struct st_table_list *tables, Item **ref);

sql/item_strfunc.cc

@@ -36,6 +36,14 @@
 
 String empty_string("",default_charset_info);
 
+static void my_coll_agg_error(DTCollation &c1, DTCollation &c2, const char *fname)
+{
+  my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
+  	   c1.collation->name,c1.derivation_name(),
+	   c2.collation->name,c2.derivation_name(),
+	   fname);
+}
+
 uint nr_of_decimals(const char *str)
 {
   if ((str=strchr(str,'.')))
@@ -316,17 +324,14 @@ void Item_func_concat::fix_length_and_dec()
   bool first_coll= 1;
   max_length=0;
 
-  set_charset(args[0]->charset(),args[0]->coercibility);
+  set_charset(*args[0]);
   for (uint i=0 ; i < arg_count ; i++)
   {
     max_length+=args[i]->max_length;
-    if (set_charset(charset(), coercibility,
-		args[i]->charset(), args[i]->coercibility))
+    if (set_charset(charset(), derivation(),
+		args[i]->charset(), args[i]->derivation()))
     {
-      my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     charset()->name,coercion_name(coercibility),
-	     args[i]->charset()->name,coercion_name(args[i]->coercibility),
-	     func_name());
+      my_coll_agg_error(collation, args[i]->collation, func_name());
       break;
     }
   }
@@ -622,18 +627,15 @@ void Item_func_concat_ws::split_sum_func(Item **ref_pointer_array,
 
 void Item_func_concat_ws::fix_length_and_dec()
 {
-  set_charset(separator->charset(),separator->coercibility);
+  set_charset(*separator);
   max_length=separator->max_length*(arg_count-1);
   for (uint i=0 ; i < arg_count ; i++)
   {
     max_length+=args[i]->max_length;
-    if (set_charset(charset(), coercibility,
-		args[i]->charset(), args[i]->coercibility))
+    if (set_charset(charset(), derivation(),
+		    args[i]->charset(), args[i]->derivation()))
     {
-      my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     charset()->name,coercion_name(coercibility),
-	     args[i]->charset()->name,coercion_name(args[i]->coercibility),
-	     func_name());
+      my_coll_agg_error(collation, args[i]->collation, func_name());
       break;
     }
   }
@@ -702,7 +704,7 @@ String *Item_func_reverse::val_str(String *str)
 
 void Item_func_reverse::fix_length_and_dec()
 {
-  set_charset(args[0]->charset(),args[0]->coercibility);
+  set_charset(*args[0]);
   max_length = args[0]->max_length;
 }
 
@@ -826,17 +828,14 @@ void Item_func_replace::fix_length_and_dec()
     max_length=MAX_BLOB_WIDTH;
     maybe_null=1;
   }
-  set_charset(args[0]->charset(), args[0]->coercibility);
+  set_charset(*args[0]);
   
   for (i=1; i<3; i++)
   {
-    if (set_charset(charset(), coercibility,
-        args[i]->charset(), args[i]->coercibility))
+    if (set_charset(charset(), derivation(),
+        args[i]->charset(), args[i]->derivation()))
     {
-      my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	       charset()->name,coercion_name(coercibility),
-	       args[i]->charset()->name,coercion_name(args[i]->coercibility),
-	       func_name());
+      my_coll_agg_error(collation, args[i]->collation, func_name());
       break;
     }
   }
@@ -876,13 +875,10 @@ String *Item_func_insert::val_str(String *str)
 
 void Item_func_insert::fix_length_and_dec()
 {
-  if (set_charset(args[0]->charset(), args[0]->coercibility,
-      		  args[3]->charset(), args[3]->coercibility))
+  if (set_charset(args[0]->charset(), args[0]->derivation(),
+      		  args[3]->charset(), args[3]->derivation()))
   {
-      my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     args[0]->charset()->name,coercion_name(args[0]->coercibility),
-	     args[3]->charset()->name,coercion_name(args[3]->coercibility),
-	     func_name());
+      my_coll_agg_error(args[0]->collation, args[3]->collation, func_name());
   }
   max_length=args[0]->max_length+args[3]->max_length;
   if (max_length > MAX_BLOB_WIDTH)
@@ -963,7 +959,7 @@ void Item_str_func::left_right_max_length()
 
 void Item_func_left::fix_length_and_dec()
 {
-  set_charset(args[0]->charset(), args[0]->coercibility);
+  set_charset(*args[0]);
   left_right_max_length();
 }
 
@@ -990,7 +986,7 @@ String *Item_func_right::val_str(String *str)
 
 void Item_func_right::fix_length_and_dec()
 {
-  set_charset(args[0]->charset(), args[0]->coercibility);
+  set_charset(*args[0]);
   left_right_max_length();
 }
 
@@ -1024,7 +1020,7 @@ void Item_func_substr::fix_length_and_dec()
 {
   max_length=args[0]->max_length;
 
-  set_charset(args[0]->charset(), args[0]->coercibility);
+  set_charset(*args[0]);
   if (args[1]->const_item())
   {
     int32 start=(int32) args[1]->val_int()-1;
@@ -1320,18 +1316,15 @@ void Item_func_trim::fix_length_and_dec()
   max_length= args[0]->max_length;
   if (arg_count == 1)
   {
-    set_charset(args[0]->charset(), args[0]->coercibility);
+    set_charset(*args[0]);
     remove.set_charset(charset());
     remove.set_ascii(" ",1);
   }
   else
-  if (set_charset(args[1]->charset(), args[1]->coercibility,
-		  args[0]->charset(), args[0]->coercibility))
+  if (set_charset(args[1]->charset(), args[1]->derivation(),
+		  args[0]->charset(), args[0]->derivation()))
   {
-    my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     args[1]->charset()->name,coercion_name(args[1]->coercibility),
-	     args[0]->charset()->name,coercion_name(args[0]->coercibility),
-	     func_name());
+    my_coll_agg_error(args[1]->collation, args[0]->collation, func_name());
   }
 }
 
@@ -1545,7 +1538,7 @@ String *Item_func_user::val_str(String *str)
 
 void Item_func_soundex::fix_length_and_dec()
 {
-  set_charset(args[0]->charset(), args[0]->coercibility);
+  set_charset(*args[0]);
   max_length=args[0]->max_length;
   set_if_bigger(max_length,4);
 }
@@ -1675,16 +1668,13 @@ void Item_func_elt::fix_length_and_dec()
     set_if_bigger(max_length,args[i]->max_length);
     set_if_bigger(decimals,args[i]->decimals);
     if (i == 0)
-      set_charset(args[i]->charset(),args[i]->coercibility);
+      set_charset(*args[0]);
     else
     {
-      if (set_charset(charset(), coercibility,
-		      args[i]->charset(), args[i]->coercibility))
+      if (set_charset(charset(), derivation(),
+		      args[i]->charset(), args[i]->derivation()))
       {
-        my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     charset()->name,coercion_name(coercibility),
-	     args[i]->charset()->name,coercion_name(args[i]->coercibility),
-	     func_name());
+        my_coll_agg_error(collation, args[i]->collation, func_name());
         break;
       }
     }
@@ -1780,17 +1770,14 @@ void Item_func_make_set::split_sum_func(Item **ref_pointer_array,
 void Item_func_make_set::fix_length_and_dec()
 {
   max_length=arg_count-1;
-  set_charset(args[0]->charset(), args[0]->coercibility);
+  set_charset(*args[0]);
   for (uint i=0 ; i < arg_count ; i++)
   {
     max_length+=args[i]->max_length;
-    if (set_charset(charset(), coercibility,
-		    args[i]->charset(), args[i]->coercibility))
+    if (set_charset(charset(), derivation(),
+		    args[i]->charset(), args[i]->derivation()))
     {
-      my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     charset()->name,coercion_name(coercibility),
-	     args[i]->charset()->name,coercion_name(args[i]->coercibility),
-	     func_name());
+      my_coll_agg_error(collation, args[i]->collation, func_name());
       break;
     }
  }
@@ -1916,7 +1903,7 @@ inline String* alloc_buffer(String *res,String *str,String *tmp_value,
 
 void Item_func_repeat::fix_length_and_dec()
 {
-  set_charset(args[0]->charset(), args[0]->coercibility);
+  set_charset(*args[0]);
   if (args[1]->const_item())
   {
     max_length=(long) (args[0]->max_length * args[1]->val_int());
@@ -1976,13 +1963,10 @@ String *Item_func_repeat::val_str(String *str)
 
 void Item_func_rpad::fix_length_and_dec()
 {
-  if (set_charset(args[0]->charset(), args[0]->coercibility,
- 		  args[2]->charset(), args[2]->coercibility))
+  if (set_charset(args[0]->charset(), args[0]->derivation(),
+ 		  args[2]->charset(), args[2]->derivation()))
   {
-    my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     args[0]->charset()->name,coercion_name(args[0]->coercibility),
-	     args[2]->charset()->name,coercion_name(args[2]->coercibility),
-	     func_name());
+    my_coll_agg_error(args[0]->collation, args[2]->collation, func_name());
   }
   
   if (args[1]->const_item())
@@ -2045,13 +2029,10 @@ String *Item_func_rpad::val_str(String *str)
 
 void Item_func_lpad::fix_length_and_dec()
 {
-  if (set_charset(args[0]->charset(), args[0]->coercibility,
- 		  args[2]->charset(), args[2]->coercibility))
+  if (set_charset(args[0]->charset(), args[0]->derivation(),
+ 		  args[2]->charset(), args[2]->derivation()))
   {
-    my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	     args[0]->charset()->name,coercion_name(args[0]->coercibility),
-	     args[2]->charset()->name,coercion_name(args[2]->coercibility),
-	     func_name());
+    my_coll_agg_error(args[0]->collation, args[2]->collation, func_name());
   }
   
   if (args[1]->const_item())
@@ -2173,7 +2154,7 @@ void Item_func_conv_charset::fix_length_and_dec()
 {
   set_charset(conv_charset);
   max_length = args[0]->max_length*conv_charset->mbmaxlen;
-  set_charset(conv_charset, COER_IMPLICIT);
+  set_charset(conv_charset, DERIVATION_IMPLICIT);
 }
 
 
@@ -2277,7 +2258,7 @@ void Item_func_set_collation::fix_length_and_dec()
       colname,args[0]->charset()->csname);
     return;
   }
-  set_charset(set_collation, COER_EXPLICIT);
+  set_charset(set_collation, DERIVATION_EXPLICIT);
   max_length= args[0]->max_length;
 }
 
@@ -2468,16 +2449,13 @@ void Item_func_export_set::fix_length_and_dec()
   uint sep_length=(arg_count > 3 ? args[3]->max_length : 1);
   max_length=length*64+sep_length*63;
 
-  set_charset(args[1]->charset(), args[1]->coercibility);
+  set_charset(*args[1]);
   for (i=2 ; i < 4 && i < arg_count ; i++)
   {
-    if (set_charset(charset(), coercibility,
-		    args[i]->charset(), args[i]->coercibility))
+    if (set_charset(charset(), derivation(),
+		    args[i]->charset(), args[i]->derivation()))
     {
-      my_error(ER_CANT_AGGREGATE_COLLATIONS,MYF(0),
-	       charset()->name,coercion_name(coercibility),
-	       args[i]->charset()->name,coercion_name(args[i]->coercibility),
-	       func_name());
+      my_coll_agg_error(collation, args[i]->collation, func_name());
       break;
     }
   }

sql/item_strfunc.h

@@ -153,7 +153,7 @@ class Item_str_conv :public Item_str_func
   Item_str_conv(Item *item) :Item_str_func(item) {}
   void fix_length_and_dec()
   { 
-    set_charset(args[0]->charset(), args[0]->coercibility);
+    set_charset(*args[0]);
     max_length = args[0]->max_length;
   }
 };
@@ -335,7 +335,7 @@ class Item_func_decode :public Item_func_encode
 class Item_func_database :public Item_str_func
 {
 public:
-  Item_func_database() { coercibility= COER_IMPLICIT; }
+  Item_func_database() { set_charset(DERIVATION_IMPLICIT); }
   String *val_str(String *);
   void fix_length_and_dec() 
   { 
@@ -348,7 +348,7 @@ class Item_func_database :public Item_str_func
 class Item_func_user :public Item_str_func
 {
 public:
-  Item_func_user() { coercibility= COER_IMPLICIT; }
+  Item_func_user() { set_charset(DERIVATION_IMPLICIT); }
   String *val_str(String *);
   void fix_length_and_dec() 
   { 
@@ -549,7 +549,7 @@ class Item_load_file :public Item_str_func
   const char *func_name() const { return "load_file"; }
   void fix_length_and_dec()
   { 
-    set_charset(&my_charset_bin, COER_COERCIBLE);
+    set_charset(&my_charset_bin, DERIVATION_COERCIBLE);
     maybe_null=1;
     max_length=MAX_BLOB_WIDTH;
   }
@@ -586,7 +586,7 @@ class Item_func_quote :public Item_str_func
   String *val_str(String *);
   void fix_length_and_dec() 
   { 
-    set_charset(args[0]->charset(), args[0]->coercibility);
+    set_charset(*args[0]);
     max_length= args[0]->max_length * 2 + 2; 
   }
 };

sql/log_event.cc

@@ -2230,7 +2230,7 @@ int User_var_log_event::exec_event(struct st_relay_log_info* rli)
   }
   Item_func_set_user_var e(user_var_name, it);
   e.fix_fields(thd, 0, 0);
-  e.update_hash(val, val_len, type, charset, Item::COER_NOCOLL);
+  e.update_hash(val, val_len, type, charset, DERIVATION_NONE);
   free_root(&thd->mem_root,0);
 
   rli->inc_event_relay_log_pos(get_event_len());

sql/sql_class.h

@@ -975,8 +975,7 @@ class user_var_entry
   char *value;
   ulong length, update_query_id, used_query_id;
   Item_result type;
-  CHARSET_INFO *var_charset;
-  enum Item::coercion var_coercibility;
+  DTCollation collation;
 };
 
 /* Class for unique (removing of duplicates) */